Development of liposomes via microfluidics for targeted eye therapies

Glaucoma presents significant challenges for effective drug delivery due to the eye’s anatomical and physiological barriers. These challenges can be addressed by developing a novel timolol maleate (TM)-loaded liposomes using microfluidics to optimize the formulation’s physicochemical properties. Nanotechnologies are able to enhance drug delivery, efficiency and reduce toxicity and side effects. Together with the meticulous control of microfluidics’ parameters such as lipid-to-cholesterol ratios, Flow Rate Ratio (FRR) and Total Flow Rate (TFR), formulations with desirable particle size below 100 nm and low polydispersity index (PDI) can be successfully achieved. The addition of DOTAP is crucial to obtain a positive z-potential, facilitating electrostatic interactions with the negatively charged ocular mucin to enhance retention and penetration. The best formulations in terms of size, homogeneity and stability, were obtained with a lipid-to-cholesterol ratio of 2:1, TFR of 1 ml/min and FRR of 1:4, and were then analysed to test the encapsulation efficiency and release of TM (Fig. 1). The drug encapsulated was released following a profile with an initial burst release followed by sustained drug delivery over 6 hours. This tailored pattern is strategically designed for nocturnal administration, aiming to minimize drug loss due to blinking and tear turnover, thereby potentially reducing dosing frequency and significantly improving patient compliance. This research successfully demonstrates the potential of microfluidic-fabricated liposomes to optimize physicochemical properties of the formulations, offering a promising pathway towards more effective, sustained and patient-friendly therapeutic management.